CVE-2026-71934: DrayTek VigorSwitch buffer overflow in pingtrace

CVE-2026-71934 · Severity: high · CVSS 7.2 · Published 2026-08-24

Multiple DrayTek VigorSwitch network switches contain a buffer overflow vulnerability in their diagnostic pingtrace function. An attacker with valid administrative credentials can send specially crafted input to overflow a fixed-size buffer, causing the device to crash or potentially execute arbitrary commands. This impacts the availability and security of critical network infrastructure.

Technologies: DrayTek VigorSwitch FX2120, DrayTek VigorSwitch G1280, DrayTek VigorSwitch G1282, DrayTek VigorSwitch G2100, DrayTek VigorSwitch G2121, DrayTek VigorSwitch G2280x, DrayTek VigorSwitch G2282x, DrayTek VigorSwitch G2540x, DrayTek VigorSwitch G2540xs, DrayTek VigorSwitch G2542x, DrayTek VigorSwitch P1280, DrayTek VigorSwitch P1281x, DrayTek VigorSwitch P1282, DrayTek VigorSwitch P2100, DrayTek VigorSwitch P2121, DrayTek VigorSwitch P2280x, DrayTek VigorSwitch P2282x, DrayTek VigorSwitch P2540x, DrayTek VigorSwitch P2540xs, DrayTek VigorSwitch P2542x, DrayTek VigorSwitch P2542xh, DrayTek VigorSwitch PQ2121x, DrayTek VigorSwitch PQ2200xb, DrayTek VigorSwitch PQ2300xb, DrayTek VigorSwitch PX2060, DrayTek VigorSwitch Q2121x, DrayTek VigorSwitch Q2200x, DrayTek VigorSwitch Q2300x. Vendors: DrayTek.

Quick answers

Is CVE-2026-71934 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-71934 being exploited in the wild.
How severe is CVE-2026-71934?
High severity, with a CVSS score of 7.2, published 24 August 2026.
Which products and versions are affected?
DrayTek VigorSwitch FX2120 before 3.9.10; DrayTek VigorSwitch G1280 before 2.9.10; DrayTek VigorSwitch G1282 before 2.9.10; DrayTek VigorSwitch G2100 before 2.9.10; and 24 more.
Is there a fix for CVE-2026-71934?
A patch was published on 2026-08-24: Firmware patches released for all affected models Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-71934 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-71934?
Check whether you run DrayTek VigorSwitch FX2120, DrayTek VigorSwitch G1280, DrayTek VigorSwitch G1282 or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A buffer overflow vulnerability exists in the pingtrace function of the VigorSwitch web management interface. The vulnerability occurs when host, count, and interval parameters are concatenated into a fixed-size buffer without proper length validation. An authenticated remote attacker can trigger this via crafted input to the web interface, causing denial of service (device crash/reboot) or potentially arbitrary code execution on the appliance. Patches are available for all affected models; exploitation requires valid administrative credentials to access the web management interface.

Affected products

  • DrayTek VigorSwitch G2540xs before 3.9.10
  • DrayTek VigorSwitch P2540xs before 3.9.10
  • DrayTek VigorSwitch FX2120 before 3.9.10
  • DrayTek VigorSwitch G2282x before 2.10.6
  • DrayTek VigorSwitch P2282x before 2.10.6
  • DrayTek VigorSwitch Q2300x before 2.10.7
  • DrayTek VigorSwitch PQ2300xb before 2.10.7
  • DrayTek VigorSwitch G2542x before 3.10.6
  • DrayTek VigorSwitch P2542x before 3.10.6
  • DrayTek VigorSwitch P2542xh before 3.10.6
  • DrayTek VigorSwitch PX2060 before 2.9.10
  • DrayTek VigorSwitch G1280 before 2.9.10
  • DrayTek VigorSwitch P1280 before 2.9.10
  • DrayTek VigorSwitch P1281x before 2.9.10
  • DrayTek VigorSwitch G1282 before 2.9.10
  • DrayTek VigorSwitch P1282 before 2.9.10
  • DrayTek VigorSwitch G2121 before 2.9.10
  • DrayTek VigorSwitch P2121 before 2.9.10
  • DrayTek VigorSwitch PQ2121x before 2.9.10
  • DrayTek VigorSwitch Q2121x before 2.9.10
  • DrayTek VigorSwitch G2280x before 2.9.10
  • DrayTek VigorSwitch P2280x before 2.9.10
  • DrayTek VigorSwitch Q2200x before 2.9.10
  • DrayTek VigorSwitch PQ2200xb before 2.9.10
  • DrayTek VigorSwitch G2100 before 2.9.10
  • DrayTek VigorSwitch P2100 before 2.9.10
  • DrayTek VigorSwitch G2540x before 2.9.10
  • DrayTek VigorSwitch P2540x before 2.9.10

Timeline

  • 2026-08-24: disclosed: Publicly disclosed by DrayTek security advisory DSA-2026-003
  • 2026-08-24: patched: Firmware patches released for all affected models

References

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